Refrigerating apparatus



June 17, 1924.

E. RUMPLER ET AL REFRIGERATI NG APPARATUS Filed June a, 1922 2Sheets-Sheet 1 Patented June 17, 1924.

UNITED STATES 1,498,123 PATENT OFFICE.

EDMUND RUMPLER, F BERlitIN-JO'HANNISTHAL, AND ALBERT RENNAU, OF BERLIN-TEGEL, GERMANY SAID RENNAU ASSIGNOR TO SAID RUMPLEIR.

REFRIGERATING- APPARATUS.

Application filed June 6,

To all whom it may concern:

Be it known that we, EDMUND RUMPLER and ALBERT RENNAU, both citizens ofthe Republic of Germany, and residents of Germany at Berlin-Johannisthaland Berlin- .Tegel, respectively, have invented certain new and usefulImprovements in' Refrigerating Apparatus, of whichthe following is aspecification.

This invention is an improvement in refrigerating apparatus of theabsorption type, which includes an evaporator, a condenser and a vesselserving alternately as a boiler and as an absorber. Upon heating theboiler a liquetiable gas is driven out of the absorbent liquid, cooledin the condenser, liquefied, and delivered to the evaporator underboiler pressure. Upon later 0001- ingthe boiler, the pressure is reducedand the liquefied gas evaporates and returns to be re-absorbed in theliquid.

The main object of this invention is to better adapt apparatus of thischaracter for use in small plants, as for instance householdrefrigerators, provision chambers or rooms where it is not practical toemploy a skilled attendant to control the operation of the apparatus andkeep it in proper working condition. 1

By means of the present invention the controlling parts are sosimplified that the apparatus can be properly controlled by a householdservant or other person unskilled in the theory of operation or detailsof construction of a refrigerating apparatus.

Furthermore, the apparatus cannot be injured by improper operation orfailure of the supply of heating or cooling medium,

and the refrigerant medium is sealed in a loss or need for replenishing,and gas cannot leak out or water or air leak in.

As one important feature of the invention there is provided a singlepipe connection from the evaporator through the condenser to theinterior of the boiler-absorber, and this pipe within theboiler-absorber may communicate with either the vapor space duringheating operation or the liquid space during absorbing operation.

As another important feature there is provided means whereby the heat isautomatically applied to the boiler upon con-- necting the pipe With thevapor space, and

closed system so that there is no liability of 1922. Serial No. 566,367.

is shut off upon connectin the pipe with the llquid space. A furtheimportant feature involves novel means whereby any liq uid which mayhave collected in the evaporator may be returned to the boiler. Afurther important feature involves the automatic control of the coolingwater upon the reversal of operation from the heating.

step to the absorbing step, or vice versa.

Other important features will be apparent from a consideration of thefollowing description and the accompanying drawings.

Fig. 1 is a diagrammatic view of one form of apparatus embodying theinvn- In the construction illustratedin Fig. 1

there is provided a vessel 10 which is adapted to serve both as a boilerand as an absorber. This vessel is connected by a conduit 11 to a secondvessel 12 which serves as a separator or dehydrator to remove from thegas any steam or liquid which may be carried along with it during theheating stage. The separator 12 is connected by a gas conduit 13 to acondenser 14, and the latter is connected by a gas conduit 15 to theevaporator 16. The evaporator is located within the chamber or room tobe cooled, while the rest of the apparatus is located outside. lVe haveillustrated di agrammatically a room or provision chamber havinginsulating walls 17. The evaporator may include top and bottom headers'18 and 19 connected by vertical pipes 20,.

and the evaporator as a whole may serve as a partition within thechamber and between storage compartments upon opposite sides, asindicated in Fig. 1 The evaporator may have a small double walled vessel21 connected thereto, and adapted to receive water which may be frozento produce a small quantity of vice.

The means for heating the boiler is shown diagrammatically as includingan electric resistance coil 22 an elec? a clock work for breaking theelectric cir-- cuit after'a predetermined time interval of boilerheating operation, aswill be more fully explained hereinafter. Thecoohng water circuit includes a supply conduit 27 leading through acondenser coil 28, thence through acooling coil 29 in the separatorchamber.- 12, and thence to a three-way valve 30. From this three-wayvalve the cooling water may flow either directly to the waste through apipe 31 or it may flow through a coil 32 disposed within or in coolingrelationship to the vessel 10. This coil is connected to the wastethrough a manually operable valve 33.

As one important tion, the gas conduit 11 between the boilerabsorber andthe separator 12 may connect either with the vapor space or with theliquid space of the boiler-absorber. As shown in Fig. 1, there isprovided a pipe 34 within the vessel 10, and pivoted .at one end. Thegas pipe 11. extends through the hollow pivotal support so as to engagewith this pipe, and the pivotal support has an external lever 35 wherebythe inner end of the pipe 34 may be raised or lowered The pipe is shownin solid lines in its raised po sition, and in dotted lines in itslowered osition. The lever 35 is connected by a ink 36to the valvelever37 of the threewayvalve 30, and an extension of this link or. aprojection on the valve lever constitutes the movable member of theswitch 25. The normal operation of the apparatus abovedescribed is asfollows. The lever 35 is moved to its lowered position which raises theopening of the pipe 34 to the gas space of the vessel10,01osestheelectric circuit at the switch 25', and turns the three-wayvalve so that the liquid flows directly from this valve throu h thewaste pipe 31. At the same time the e ectric circuit is closed at theclock work 26, and the clock work started. The electric current throughtheresistance coil 22 causes the liquid in the vessel 10 to be heated,and the liquefiable gas (preferably I ammonia) isdriven off through thepipe 34" and gas pipe 11 to the separator 12. Here any steam carriedalong by the gas is condensed while the gas travels on through the pipe13-to the condenser 14, and the resulting liquefied gas flows on to theevaporator. After a predetermined interval of heating operation thelever 35 should be shifted to the raised position. This will lower thepipe 34 to a point below the liquid level in the vessel 10, will breakthe electric circuit at the switch'25, and will turn the three-wayvalve. 30 so that thecooling' water will now flow from this valvethrough the feature of the inven-.

condenser and separator to the vessel 10, and i will enter the liquidata point below the level of the latter so that thevessel 10 now servesas an absorber. The gas pipe 11 leads from the lowest point in theseparator 12 so that any liquid which may have been car ried over intoor condensed in the separator will be returned to the main body ofliquid in the vessel 10. The rapidity of the evaporation of' theliquefied gas and the heat absorbing efiect in the chamber 17 will varywith the speed at which the gas is reabsorbed in the liquid, and thiswill vary with the speed or extent to which the temperature of theliquid is lowered. This may be readily controlled by properly settingthe valve 33.

With this valve wide open, there will be a rapidity of the evaporationof the liquefied gas may bereduced with corresponding lessening of therefrigerating effect but lengthening of the time interval betweensuccessive heating periods. After the apparatus is installed the valvemay be properly set by experiment and will not ordinarily need to bechanged except possibly to have it open a little wider for summer thanfor winter operation.

It will be noted that the water supply is delivered continuously throughthe coil 28 of the condenser, and the coil 29 of the separator,irrespective of whether or not it passes through the coil 32 of theabsorber. Thus, the gas produced in the evaporator comes into heatinterchanging relationship with the cooling water in both the coil andthe separator before the gas re-enters the absorber, and before thewater flows to the coil 32. Thus the water in the coil has itstemperature reduced materially below that of the ordinary water supply,and is therefore capable of cooling the absorber to a comparatively lowtemperature, and facilitating the very rapid cooling of the absorber orthe cooling of it to such a low temperature that there is the maximum orsubstantially complete 'reabsorption of -the, gas from the evaporator.

It will be noted that the only operation which it is necessary for theattendant to perform is the lowering of the lever 35 when the heatingoperation is to begin, and raising it When the heating operation iscompleted.

' gets to shift the lever when the gas has been driven out of the liquidand re-liquefied inthe evaporator, no damage will be done to theapparatus. The clock work switch breaks the electric circuit and stopsthe heating operation, and even though the lever 34 remains in itsraised position and the three-Way valve 30 keeps the water shut off fromthe coil 32, there will still be a slow coolingof the boiler byradiation to the atmosphere and a slow re-absorption of the gas withcorresponding evaporation from the evaporator. The only effect will be avery much reduced cooling action in the evaporator.

As one important feature of .the invention there is provided a pipeconnection 39 between the gas-pipe 13 and the lowermost point of theevaporator. This pipe 39 is connected to the gas pipe 13 by a three-wayvalve 40 which is normally in the position indicated so as 'to providefree flow therethrough between the absorber and condenser, and to closethe upper end of the pipe 39. If during shipment of the apparatus orduring long continued use, liquid collects in the evaporator, suchliquid may be easily and quickly returned to the vessel 10. After theend of the heating operation the threeway valve may be turned so as toconnect the pipe 39 with the separator 12.

.As the pressure in the separator and vessel 10 drops for thebeginningof the absorption step of the process, the partial vacuum produced,together with the accumulated pressure in the upper part of theevaporator will force any liquid in the lower portion :of the evaporatorup through. the pipe 39 and past the three-way valve 40 to the gas pipe13, and thence through the separator and pipe 11 to the vessel 10. Thisstep need be performed'only at very infrequent intervals, as in thenormal operation little or none of the water from theboiler 'can reachthe evaporator, as it will be condensed and separated out in theseparator 12. The time interval for -theshifting of the lever 35 may bedetermined by experiment for each type of apparatus, and the clock workmay be set in accordance with the time each experiment shows isnecessary for the heating period. Obviously the heating period will 7 bevery short compared to the absorbing and cooling period, and inapparatus which has been built a heating period of one hour eachtwenty-four hours is sufieient.

We do not wish to be limited to the specific means shown in Fig. 1 forestablishing communication between the gas pipe 11 and either the vaporspace or the liquid space of the boiler.

In Fig. 2 we have illustrated diagrammatically a system similar to thatshown in Fig. 1, but with more complete electrical control. The ipe 34within the boilerabsorber, instea of having a manually operable handle,as in Fig. 1 has an electromagnet 42 for raising it when the circuit isclosed. The valve 30 in the water circulating system also has anelectro-magnet 54 acting against a spring 55 and serving to control theflow of cooling water to the coil 32 of the boiler-absorber. Theelectromagnets 42 and 54 are in the same electric circuit with theheating coil 22, so that when the circuit is closed at the switch 25,the heat will be turned on, the ipe 34 will be raised to bring itsopening a ove the liquid level, and thevalve 30 will be turned to shutoff the water from flowing to the coil 32. The valve 30 is so positionedthat the water supply entering from the pipe 27 may flow either throughthe pipe 56 to the cooling coil 32 of the absorber, and thence to thewaste 57, or it may flow from the pipe 27 to the pipe 58, thence throughthe condenser 14 to the outlet 59, and then to the waste. tocontrol onlythe flow through the pipe 56, while permitting a continuous flow throughthe pipe 58 and the condenser. A valve 60 at the outlet of the coil 32may be set to regulate the flow through the coil, and thus control therapidity of the cooling eflfect. The evaporator is diagrammaticallyillustrated as including a container 61 and a coil 62, and within thecontainer may be a pocket or chamber 63 in which water may be frozen toform ice. The container and evaporating coil may if desired be in aseparate compartment having a closure 64 in the nature of a venetianblind so that the air around the evaporator may be prevented fromcirculating around the main portion of the room to be cooled during theheating period when there is no evaporation of liquefied gas takinplace.

The switch 25 may be closed manually or in any other suitable way forstarting the heating effect, and when the gas has been driven off, theswitch may be manually opened or the circuit may be interrupted by clockwork, as shown in Fig. 1, or in any other suitable way. Forautomatically open- The valve 30 may be such as.

ing the circuit, recourse may be had to a heat responsive element, suchas a thermometer 65 controlling an electric cricuit 66 which in turn maybe utilized in any well known manner for instance through a relay forcontrolling the main electric circuit, which includes the heater 22 andthe mag nets 42 and 54. v

In Fig. 3 there is illustrated diagrammatically an apparatus which maybe utilized for automatically turning on and off the current at thedesired time intervals. A clock work serves to rotate a disk 67continuouslyand at uniform speed. The main portion of this disk is ofinsulation, but a contact portion 68 will serve once during eachrevolution to connect the circuit across a pair of brushes 70. Thesebrushes may be in the main electric circuit which includes the heatingcoil 22, the electro-magnet 4:2 and if desired the additionalelectro-magnet 54. The length of the contact strip 68 will control thetime of the heating period. It will be noted that this is comparativelyshort in respect to the circumference of the disk 67. l

While we have specifically referred to electric means for heating theboiler liquid, it is understood that other heating means are applicable.In Fig. 2 inclusive the heating unit is indicated as being Within a tubeor cartridge adapted to be slipped into a pocket or recess in theboiler. This permits the cartridge to be removed and replaced orrepaired without opening up the boiler. If other form of heating meansshould be employed, as for instance a gas burner, the same electriccircuit as disclosed in Figs. 1, 2 and 3 might be employed but a magnetin the circuit would operate to turn on and off the supply valve ofrtheburner leaving only a small pilot light burning. I

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A refrigerating apparatus comprising a vessel containing a liquidadapted to alternatelyoperate as a boiler and as an absorber, anevaporator, a fluid connection between the vessel and the evaporator,said connection including a tube disposed in the vessel and movablerelatively thereto, and a lever member for moving the tube to a positioninwhich its free end is immersed in the liquid or to a position in whichit -is disposed above the level of the liquid.

2. A refrigerating apparatus comprising a vessel containing a liquidadapted to alternately operate as a boiler and as an absorber, anevaporator, a fluid connection between the vessel and the evaporator,sai connection including a tube disposed in the vessel and movablerelatively thereto, a handle member for moving the tube to a position inwhich its free end is immersed in the liquid or to a position in whichit is disposed above the level of the liquid, means connected to saidhandle member for effecting the supply of heat to said vessel when thetube is in the last mentioned position and shutting off the supply ofheat when in the first mentioned position.

3. A refrigerating apparatus comprising a vessel containing a liquidadapted to alternately operate as a boiler and as an absorber, anevaporator, a fluid connection between the vessel and the evaporator,said connection including a tube disposed in the vessel and. movablerelatively thereto, a lever member for moving the tube to a position inwhich its free end is immersed in the liquid or to a position in whichit is disposed above the level of the liquid, and means for supplyingcooling liquid in heat interchanging relationship to said vessel whensaid tube is in the first mentioned position.

4. A refrigerating apparatus comprising a vessel containing a liquidadapted to alternately operate as a boiler and as an ab- I sorber, anevaporator, a fluid connection between the vessel and the evaporator,said connection including a tube disposed in the vessel and movablerelatively thereto, a handle member for moving the tube to a position inwhich 'its free end is immersed in the liquid or to a position in whichit is disposed above the level of the liquid, means for heating saidvessel when said tube is in the second mentioned position, and means forcooling said vessel when said tube is in the first mentioned position;

5. In a refrigerating apparatus, a closed vessel containing aliquidadapted to absorb a gas, a gas tube for delivering gas therefrom orthereto and havingan opening disposed within the vessel, a handle memberfor changing the relative position of the liquid level and the openingof the tube to either immerse the opening of the tube in the liquid orto'dispose it above the level of the liquid, a valve for supplyingcooling liquid to said vessel, an electric heating ele- 'ment in thevessel, a switch for controlling the supply of electric heating currentto said vessel, and connections between said handle member, valve andswitch for operating them simultaneously.

Signed at Berlin, Germany, this 18th day d of May, A. D. 1922.

EDMUND RUMPLER. ALBERT RENNAU. \Vitnesses:

E. H. HERMAN, R. G. ALLsPALL.

